Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B17/00—Monitoring; Testing
  • H04B17/20—Monitoring; Testing of receivers
  • H04B17/29—Performance testing
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04B—TRANSMISSION
  • H04B17/00—Monitoring; Testing
  • H04B17/10—Monitoring; Testing of transmitters
  • H04B17/15—Performance testing
  • H04B17/19—Self-testing arrangements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W24/00—Supervisory, monitoring or testing arrangements

Definitions

• the invention relates to a method for testing a transceiver unit in a time-divisional radiocommunica ⁇ tion system, said method comprising supplying a prede ⁇ termined test signal from the transmitter to the receiver, and subsequently comparing the test signal transmitted with the test signal received, and to a base station of a time-divisional radiocommunication system, said base station comprising at least one transceiver unit and a test unit for testing the operation of the transceiver unit, said test unit comprising mixing means for converting the test signal transmitted by the trans- mitter of the transceiver unit from transmission frequency into reception frequency, the output of said mixing means being arranged to supply the test signal of the reception frequency to the receiver, and control means for supplying test data to the transmitter of the transceiver unit and for comparing the output signal of the receiver with the test data supplied to the trans ⁇ mitter.
• TDMA Time Division Multiple Access
• GSM Global System for Mobile Communications
• test devices The structure of known test devices is very complicated owing to the delay components they contain for providing the delay mentioned above, e.g. the delay of three time slots according to the GSM Specifications.
• these delay components are either analog or digital, in which case they comprise an analog-to-digital converter, a digital shift register and a digital-to-analog converter.
• the invention also relates to a base station which is characterized in that said base station comprises means for selecting two free time slots of the transceiver unit and for assigning them for the test, the control means of the transceiver unit conducting the testing of the operation of the unit using the selected time slots in such a manner that the transmitter transmits a test signal using the first selected time slot and the receiver receives the test signal using the second selected time slot.
• Figure 1 shows part of a preferred embodiment of the base station according to the invention.
• FIG. 1 illustrates a transceiver unit 1 of a base station in the GSM system.
• the unit 1 illustrated in the figure tests the operation of the components of its transmitter
• the base station controller 4 selects two free time slots, e.g. time slots 4 and 1 (shown in Figure 2), which do not carry any traffic at that par ⁇ ticular moment.
• the time slots are selected in such a manner that when the transmitter 2 of the transceiver unit 1 transmits on the first selected time slot, e.g. on time slot 4, the receiver 3 receives the second selected time slot, e.g. time slot 1.
• the control unit 5 in the baseband section 13 of the transceiver unit 1 switches on the oscillator 6 of the transceiver unit.
• the oscillator 6 is thus switched on before the actual test is started to allow it to settle before the actual test.
• a suitable settling time is, for example, 10 ms.
• the control unit 5 of the transceiver unit 1 switches on a mixer 7 by means of an RF switch 8 while supplying predetermined test data to the input of the transmitter 2 through a frame unit 11.
• the transmitter 2 transmits the test data supplied to it, using the first selected time slot, e.g. time slot 4.
• the output of the transmitter 2 is connected via a directional coupler 9 to the mixer 7, which under the control of the control unit 5 operates during the test period, converting the test signal into reception frequency.
• the output of the mixer 6 is connected to a directional coupler 10, by means of which the signal of reception frequency is supplied to the input of the receiver 3 on the second selected time slot, e.g. time slot 1.
• the test loop consisting of components 7, 9 and 10 does not comprise any components intended to introduce delay.
• the output signal of the receiver 3 is supplied through the frame unit 12 to the control means 5, which compares the received test signal and the predetermined test data supplied to the transmitter 3 through the frame unit 11.
• the comparison can be made, for instance, by calculating the bit error ratio (BER) and comparing it with a predetermined reference value. If the bit error ratio obtained by calculation exceeds the refer ⁇ ence value, the control means 5 sends information on this to the base station controller 4.
• BER bit error ratio
• the transceiver unit to be tested is of a type comprising a diversity branch (DIV RX), this branch can also be tested in addition to the actual receiver branch. If it is then observed that the normal receiver gives high BER results and the diversity branch gives normal BER results, the transceiver unit can be adjusted so as to use only the diversity branch, whereby the diversity function is naturally lost.
• DIV RX diversity branch
• Figure 2 is a schematic representation of how the time slots to be used should be selected for the testing of a transceiver unit in the GSM system.
• the GSM Specifications require that a mobile station should have a delay of three time slots between reception and trans ⁇ mission.
• Figure 2 illustrates the effect of a delay of three time slots on the operation of a base station.
• the transmitter indicated by reference number 2 in Figure 1
• the receiver indicated by reference number 3 in Figure 1
• the structure and operation of the GSM system is described in The GSM System for Mobile Communications by M. Mouly and M-B. Pautet, Palaiseau, France, 1992, ISBN: 2-9507190-0-7.
• two time slots must thus be assigned for the test in order that the need of delay components in the test loop (components 7, 9 and 10 in Figure 1) could be avoided and the test signal transmitted by the transmitter could be immediately supplied to the input of the receiver.

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• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Engineering & Computer Science (AREA)
• Computer Networks & Wireless Communication (AREA)
• Signal Processing (AREA)
• Mobile Radio Communication Systems (AREA)
• Monitoring And Testing Of Transmission In General (AREA)
• Time-Division Multiplex Systems (AREA)
• Saccharide Compounds (AREA)
• Investigating Or Analysing Biological Materials (AREA)

Priority Applications (6)

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Publications (1)

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ID=8538119

Family Applications (1)

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Cited By (5)

Families Citing this family (20)

Citations (4)

Family Cites Families (4)

• 1993
  • 1993-06-11 FI FI932699A patent/FI109740B/fi active
• 1994
  • 1994-06-06 EP EP94917007A patent/EP0655179B1/en not_active Expired - Lifetime
  • 1994-06-06 US US08/379,661 patent/US5604728A/en not_active Expired - Lifetime
  • 1994-06-06 DE DE69421364T patent/DE69421364T2/de not_active Expired - Fee Related
  • 1994-06-06 AU AU68467/94A patent/AU675545B2/en not_active Ceased
  • 1994-06-06 CN CN94190371A patent/CN1051186C/zh not_active Expired - Fee Related
  • 1994-06-06 WO PCT/FI1994/000240 patent/WO1994029976A1/en active IP Right Grant
  • 1994-06-06 JP JP07501372A patent/JP3098037B2/ja not_active Expired - Fee Related
  • 1994-06-06 AT AT94917007T patent/ATE186163T1/de not_active IP Right Cessation
• 1995
  • 1995-02-10 NO NO19950523A patent/NO311548B1/no unknown

Patent Citations (4)

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